Estimation of in-plane Irradiance by Regression Analysis of Irradiance data from Residential PV Systems

摘要

The estimation system to characterize PV systems, which can be used to get typical in-plane irradiance of PV systems together with the global irradiance at the place, was proposed. The system consists of the monthly regression functions R(t) of the minutely ratio of in-plane and global irradiance separated by clearness ratio. The irradiation data in three years for 100 residential PV sites in Japan were used to calculate and analyze the regression coefficients of these sites. With the results of the analysis, we obtained the useful relations between the regression coefficients, sky conditions and installing orientations of PV sites. These are the basic relations to estimate the in-plane irradiance of other PV systems without completely measured data.